Published online by Cambridge University Press: 14 August 2015
The present state of the Palomar Proper Motion Survey is described. Before the CDC automated-computerized plate scanner became operational in 1972, 153 plate pairs had been blinked, whereas since then 443 pairs have been machine processed. Of the remaining 350 fields, some 40 are probably beyond the capability of the present system due to excessive star density.
Some 21000 new motions larger than 0″.18 annually have been published. The accuracy of an individual motion is about ± 0″.016 from a single machine-processed plate pair, as compared with ± 0″.025 from hand measured plates.
There is an indication that the number of large motions per unit area increases with galactic latitude.